The Chemical Appeal of Silver Alloy-Infused Jewelry

August 26, 2012byDavid Federman

Scores of new silver alloys that claim to offer more shine than sterling for only a small premium have recently come to market, but the metallurgy has proved confusing to buyers. JCK makes sense of the chaos.

Talk to silversmiths like Sam Patania about any of the dozen or so tarnish-resistant silver alloys that have come on the market during the past decade and they’ll praise them to the skies. Funny thing, though, their praise doesn’t include the attribute for which the ­jewelry industry knows these alloys best: anti-tarnishing.

Sure, Argentium, Sterilite, Sterlium, TruSilver, and the like keep silver shining for months and even years. And there’s no doubt that extended luster life saves valuable time by freeing employees from weekly silver cleaning and brightening tasks. “Maintenance-free ­silver is a dream come true,” says Bill Hoefer, a Tampa, Fla.–based appraiser, silversmith, and former store owner. “Have you ever had a wall full of silver you had to have employees take down weekly for polishing? If nothing else, you have to be grateful to tarnish-­resistant silver for eliminating a lot of the grunt work associated with sterling.”

Nevertheless, low- or no-care silver is more important to jewelry buyers and sellers than to jewelry makers. Patania looks at tarnish-resistant silver through the eyes of a visionary, not a vendor. “Face it, patina is the natural fate of silver,” says the Tucson, Ariz.–based studio jeweler. “All silversmiths want patina. The idea of eternal youth for a piece of silver jewelry is silly. There is nothing wrong with looking your age when you age with grace.”

Patania gives two technical reasons: stain prevention and greater manufacturing possibility. “When it comes to ­tarnish-resistant alloys, it’s what you don’t see that matters as much as what you do,” Patania says. And what you don’t see is ugliness. “Ugliness,” he adds, “that tarnish-resistant alloys eliminate before it happens.”

Stainless Silver

The case for tarnish-resistant silver boils down to one ­truism: An ounce of prevention is worth a pound of cure. In this case, it might even be tons. Never forget that the ­greatest bane of silver jewelry manufacturing is fire scale, also known as fire stain. Put simply, this condition is a form of metallurgical “sunburn” that occurs when the copper used as a hardener in the standard sterling alloy mixes with oxygen at high temperatures. The result is unsightly purplish discolorations.

Fire stain can be a consequence of both alloying and workmanship. Although some fire stain can be removed, it is an arduous, time-consuming, and potentially hazardous process. “Every silversmith makes mistakes,” says Dallas studio jeweler Patricia Tschetter, “and fire scale is a price they often pay.” What is needed is an alloy with some ingredient that acts as a kind of permanent sunscreen. ­Tschetter welcomes alloys such as Argentium and their “burn-­blocking” abilities as a godsend. So does Hoefer. “I see the development of tarnish-resistant alloys as beneficial as the discovery of a vaccine,” he analogizes. “Suddenly, ­silversmiths are freed from the most common form of ­failure and the fear of such failure.”

The elimination of fire scale produces what might be described as clean-complexioned sterling. What’s more, once you eliminate fire stain, you eliminate a common need and temptation to plate silver with silver as a form of white-out and cover-up. “Just because you are putting pure silver on top of sterling does not make the top layer any less a form of plating,” Hoefer notes.

Look, Ma—No Solder!

If tarnish-resistant alloys did nothing other than retard blackening of silver and prevent fire scale, they still would represent epochal evolution in the millennial history of silver jewelry. But there’s one more gigantic contribution they have made to bench life. They have eliminated the need to solder parts of pieces. “The fusion properties of these alloys is nothing short of amazing,” exclaims Tschetter. All those signature sterling pellets that she uses in great profusion are joined by sheer metal attraction alone.

Patania likewise applauds these mixtures for what he calls their “superior weldability.” He continues: “Take a look around my workshop. Most of the pieces you’ll find here would have been impossible to make a decade ago. Tarnish-resistant alloys improve the fusing of the metal—from sheet to solder. I can make assembled, multipart pieces I would never have attempted in the old days.”

In short, tarnish-resistance isn’t just about extended whiteness and brightness; it’s as much about risk reduction and increased design capability. “All of these technical innovations add up to new creative possibilities and visionary vistas for silver jewelry,” Hoefer says. “Tarnish-resistant alloys have given the art of silversmithing its biggest boost in centuries.”

What Took So Long?

If tarnish-resistant alloys were so needed, why did the jewelry industry have to wait until the dawn of the 21st century to find them? Time out for a history lesson.

When it comes to the short history of tarnish-resistant alloys, time lines should be marked B.G. and A.G.—that is, before germanium and after. This element is a latter-day addition to the periodic table that was discovered in 1886 by the German chemist Clement Winkler, who named the metal after his homeland. When germanium finally found industrial use after World War II, it was mostly as a semiconductor and transistor. Later, germanium, which is transparent to infrared light, found a new application in night-sighting instruments. But with the end of the Cold War, military demand dropped off and the search was on for new uses.

Enter Peter Johns, a silversmith and professor at England’s Middlesex University’s School of Art and Education. In 1990, Johns was approached by Metaleurop S.A., a French mining company with huge but idle reserves of germanium, to investigate the metal’s possible use in jewelry making. During his experiments, he discovered that when used as an additive with sterling silver, germanium produces a surface oxide layer that acts as a tarnish-retardant barrier—not just once but repeatedly. Because germanium’s small, highly mobile atoms are free to keep migrating to the alloy’s surface, they continually regenerate a protective layer.

Besides defending sterling against tarnish, germanium-based alloys acted as a deterrent to fire stain. Johns discovered that the self-renewing oxide shield of germanium functions as a block to the oxygen that at high temperatures would otherwise attack and discolor the copper.

Once there was an alloy that could eliminate the constant danger of fire scale, sterling silver could become one of the world’s most ­eco-friendly metals by sparing artisans the need for toxic acids to dissolve purplish blotches (many of which are indelible). More important, ­germanium-based alloys end the need to plate with very toxic chemicals to camouflage unsightly mistakes. It also rendered pieces hypoallergenic.

Johns’ germanium-based alloy and its subsequent variants were trademarked as Argentium (an acronym for silver and germanium). Today there are at least five Argentium alloys made with both .935 and .960 silver content; in addition, several American refiners have introduced germanium-based silver alloys. Each one, of course, has its advocates. No doubt, more germanium-based alloys will be introduced, especially as early Argentium patents expire and refiners are free to produce generics of the first-generation formulas. Johns, who says that new patented Argentium-brand alloys are now in the market, welcomes the competition. “There’s nothing like free enterprise to keep you on your toes,” he says. “No one in the silver alloy field is resting on their laurels.”